strategic allies: Armenian President Serzh Sarkisian (right) has agreed to let Russian President Vladimir Putin deploy a slew of military vehicles to a base just outside the Armenian capital of Yerevan. (Associated Press) more >

The clash between Russia and Turkey is not just taking place in the skies over Syria. It’s also spreading to the nearby Caucasus region, where a fresh wave of Russian military overtures to Armenia threatens to reignite a frozen conflict that has pitted Moscow against Ankara for decades.

Given Russian President Vladimir Putin’s anger over the downing of a Russian fighter jet by Turkish forces in November, Moscow has spent the past several months beefing up its military footprint in Armenia, a country of roughly 3 million people that shares a 165-mile border and a land-mine-filled history with Turkey.

After quietly signing an air defense agreement with the tiny former Soviet republic in December, Moscow has deployed at least four new MiG-29 fighter jets and a slew of other military vehicles to a Russian base just outside the Armenian capital of Yerevan.

The moves constitute a case study in how the multinational, multifront conflict in Syria is spilling into other theaters, widening the zone of instability and heightening tensions between countries such Iran and Saudi Arabia, as well as Turkey and Russia.

According to Russian news reports, the air defense agreement was in the works for months. But the shipment of MiGs and new Russian helicopters in mid-February appears to have been Mr. Putin’s way of warning Turkey and its NATO allies of Moscow’s capacity to make trouble in the region.

U.S. analysts are divided over the extent to which Armenia — which is wedged against Iran, Turkey and Russia — is actively aligning itself with the Russians or simply being bullied by Moscow as a pawn in Mr. Putin’s push to surround Turkey.

“Clearly, Armenia has a close and historic relationship with Russia, and now that Turkish-Russian relations are in a death spiral, it has become a front-line state in the context of that confrontation,” said Ariel Cohen, a senior fellow at the Atlantic Council in Washington.

But even as the prospect of a deepening Russia-NATO clash looms, the more immediate fear is that Moscow’s recent moves may reignite an ethnic war in the Caucasus, particularly the long-simmering dispute over the Nagorno-Karabakh region, pitting Armenia against its eastern neighbor Azerbaijan.

The separatist Nagorno-Karabakh enclave inside Azerbaijan has been under the control of Armenia’s military and local ethnic Armenians since all-out war between the two former states of the former Soviet Union ended there in 1994.

“The biggest explosive potential here is not vis-a-vis Turkey; it’s vis-a-vis Azerbaijan and Nagorno-Karabakh,” said Mr. Cohen. “That’s the main powder keg in that part of the world.”

“Karabakh is intertwined in all of this,” Mr. Burke said. “With the frozen Karabakh conflict, and now the Russia-Turkey tensions, there are just a whole lot of people playing with matches in the region and sometimes fires begin accidentally.”

The conflict’s aftermath has long been a bone of contention between Turkey and Russia. Armenia’s relationship with Turkey has been shadowed by Armenian charges that the Turks engaged in a genocide against its ethnic Armenian minority during World War I.

Cashing in

While Ankara sided with the Azerbaijani government, imposing a trade embargo on Armenia, Moscow has exerted influence across the board, selling weapons to both the Armenians and the Azerbaijanis.

The Russians now appear to be cashing in by pressing Armenia to accept an expanding Russian military footprint on Turkey’s doorstep. And because of Nagorno-Karabakh, the Armenians, whose economy and military are heavily dependent on Russia, appear to have little choice in the matter.

“If Armenia tells Russia to take a hike, Russia has the leverage in Karabakh to impose a solution to the frozen conflict that would favor Azerbaijan,” said Mr. Burke. “Armenia really doesn’t have an ally in the neighborhood. It’s surrounded by hostile states,” he said. “Any notion that Armenia is a willing client state in lockstep with Moscow is a distortion.

“It’s far more complex than that,” Mr. Burke added.

“Armenia is not a Kremlin pawn,” he said. “Many leaders in Yerevan are worried about getting dragged into the Russia-Turkey confrontation.”

Others argue that Moscow is effectively turning Armenia into a “satellite state” for Mr. Putin to exploit as he pushes to challenge Turkey for regional dominance. That push gained steam with the 2014 annexation of Ukraine’s Crimean Peninsula.

The two years since have brought a deepening of relations between Russia and Iran to Turkey’s east, as well as Moscow’s growing military support for the Bashar Assad regime in Syria to Turkey’s south.

Adam Ereli, a former State Department spokesman and ambassador to Bahrain who now works for a public affairs firm representing a pro-Turkish group, warned that Russian military shipments to Armenia, in addition to the MiG-29 deployments, “has escalated to include advanced Navodchik-2 and Takhion UAV drone aircraft, Mi-24 helicopter gunships and Iskander-M ballistic missiles.”

Writing in Forbes magazine, Mr. Ereli cited Russian media reports that Mr. Putin actually began ordering snap combat readiness checks of some 5,000 Russian troops stationed in Armenia as far back as July. In early February, Russia began a massive military exercise in its southwest.

“The total strength of the regional operation included approximately 8,500 troops, 900 ground artillery pieces, 200 warplanes and 50 warships,” he wrote.

“A similar Russian deployment on the borders of any other NATO member state would produce an outcry of outrage,” he wrote. “Why are we staying silent in the face of this thinly veiled aggression against Turkey?”

But an official at NATO headquarters in Belgium said some of the fears of Moscow’s recent moves are overstated.

“Sure, there is a Russian military base in Armenia and the Russians do exercises with the Armenians and they are on the border with NATO,” said the official, who spoke on the condition of anonymity. “But I don’t see this as anything different from what the Russians have been doing in Armenia over the past 10 years. It’s not a new threat that we see.

“The real thing to understand here is that Armenia doesn’t have a choice,” said the official, who added that the feeling inside NATO is that the Armenians are stuck balancing between Moscow and the West.

“The Armenians don’t have a bad relationship with NATO,” the official said, noting that Yerevan has actually committed troops to NATO’s mission in Afghanistan as well as to Kosovo.

That being said, the official agreed that there are some in Moscow who seek to exploit Armenia’s geographic proximity to Turkey as a way of adding pressure to Ankara.

“The real question is: Will the Armenians let them?” the official said. “If the Russians start flying sorties up against the Turkish border from Armenia, then it certainly becomes a problem for Turkey and for NATO.

“But that’s not happening yet because the Armenians haven’t allowed the Russians to do it. The Russians don’t just do whatever the hell they want in Armenia. It’s an independent country. The Armenians would have to give a green light for that, and so far they haven’t.”